This invention relates generally to food rethermalization. More particularly, this invention relates to systems and methods for refrigerating, reheating, and serving prepared meals in an institutional setting.
Food rethermalization units are used by institutions, such as hospitals, to store prepared trays of food in a refrigerated state. The trays generally have an area for storing cold-served foods, e.g, milk, fruit, salads, and the like, and an area for storing hot-served foods, e.g., entrees, potatoes, vegetables, and the like. The units maintain the foods in a refrigerated state and have a rethermalization capability wherein hot-served foods are reheated to a desired serving temperature prior to their being served.
The present invention is directed to a rethermalization system for use with food trays having a hot side and a cold side. The system is operable to maintain both the hot side and the cold side of each tray at a cold temperature and of heating the hot side from the cold temperature to a hot temperature while simultaneously maintaining the cold side at the cold temperature.
In a preferred embodiment, the system includes a plurality of food trays, each tray having a cold food side and a hot food side, and a rethermalization unit having a first compartment accessible via a first end and configured for being loaded with the trays. A first thermal system is located adjacent a first interior side of the rethermalization unit so that when the trays are received within the first compartment the hot food side of each tray is directly adjacent the first thermal system for thermal treatment thereby. A second thermal system is located adjacent a second interior side of the rethermalization unit so that when the trays are received within the first compartment the cold food side of each tray is directly adjacent the second thermal system for thermal treatment thereby.
A compressor system is operatively associated with the first and second thermal systems. A microprocessor-based control system controls operation of the first and second thermal systems and the compressor system to effect desired thermal treatment of food on the food trays.
In one aspect of the invention, the first thermal system includes a heating source, a refrigeration coil, and a blower for circulating heat from the heating source and cold from the refrigeration coil. The second thermal system preferably includes first and second refrigeration coils and a blower for circulating cold from the first and second refrigeration coils. The control system is operable so as to activate the refrigeration coil of the first thermal system and the first refrigeration coil of the second thermal system and to deactivate the second refrigeration coil of the second thermal system when the rethermalization system is operated to maintain both the hot side and the cold side of each tray at a desired cold temperature. The control system is further operable to deactivate the refrigeration coil of the first thermal system, activate the heating source of the first thermal system, and activate both the first and second refrigeration coils of the second thermal system when the rethermalization system is operated to heat the hot side from the desired cold temperature to a desired hot temperature while simultaneously maintaining the cold side at the desired cold temperature.
In another aspect, the system includes a cassette configured for receiving the plurality of the trays and a cassette placement sensor located within the rethermalization unit. The sensor is operatively associated with the control system for sensing initial placement of the cassette within the rethermalization unit. The control system initiates operation of the first and second thermal systems when the cassette is placed in the rethermalization unit to maintain both the hot side and the cold side of each tray at a desired cold temperature.
In yet another aspect, the system includes a compressor system temperature monitor and/or a compressor pressure monitored associated with the compressor system for sensing temperatures and/or pressures associated with the operation of the compressor system. The monitors are operatively associated with the control system for inputting temperature and/or pressure information thereto relating to the compressor system. When the temperature or the pressure of the compressor system exceeds a predetermined value the control system generates a signal to cease operation of the compressor system.
In still another aspect, the system includes a cassette configured for receiving the plurality of the trays, a first portage unit, and a second portage unit. The first and second portage units are each configured for receiving the cassette and for transferring the cassette to the first compartment and for removing the cassette from the first compartment of the rethermalization unit.
The rethermalization unit includes a first latch pin adjacent the first compartment and the first portage unit has a first end including a first latch system releasably engageable with the first latch pin (and a latch pin of the second portage unit). The second portage unit has first and second opposite ends, the first end of the second portage unit having a second latch system releasably engageable with the first latch pin and a second latch pin releasably engageable with the first latch system of the first portage unit. If desired, a plurality of the second portage units may be connected to one another via their receptive latch systems and latch pins.
The invention also relates to a method for rethermalizing food trays having a hot side and a cold side to maintain both the hot side and the cold side of each tray at a cold temperature for a desired period of time and thereafter heating the hot side from the cold temperature to a hot temperature while simultaneously maintaining the cold side at the cold temperature,.
In a preferred embodiment, the method includes the steps of providing a plurality of food trays, each tray having a cold food side, a hot food side and providing a rethermalization unit configured for being loaded with the trays, the rethermalization unit having a first thermal system including a heating source and a refrigeration source, and a second thermal system including first and second refrigeration sources.
The rethermalization system is preferably initially operated to maintain both the hot side and the cold side of each tray at a desired cold temperature by activating the refrigeration source of the first thermal system and the first refrigeration source of the second thermal system and deactivating the second refrigeration source of the second thermal system. The rethermalization system is subsequently operated to heat the hot side from the desired cold temperature to a desired hot temperature while simultaneously maintaining the cold side at the desired cold temperature by deactivating the refrigeration source of the first thermal system, activating the heating source of the first thermal system, and activating both the first and second refrigeration sources of the second thermal system.
In a further aspect, the method involves the steps of providing a rethermalization unit configured for being loaded with the trays, the rethermalization unit having a thermal system to selectively provide heating and cooling to the unit, a cassette configured for receiving the plurality of the trays, and a cassette placement sensor for sensing initial placement of the cassette within the rethermalization unit, and sensing when the cassette is initially placed in the rethermalization unit and initiating operation the thermal system to maintain both the hot side and the cold side of each tray at a desired cold temperature when the cassette is placed in the rethermalization unit.
In yet another aspect, the invention relates to a method for handling food trays to be selectively refrigerated and rethermalized.
In a preferred embodiment, the method includes the steps of providing a plurality of food trays, providing a cassette configured for receiving the plurality of the trays; providing a rethermalization unit configured for being loaded with the trays, providing a plurality of portage units selectively interconnectable to one another and each portage unit being configured for receiving the cassette and for transferring and removing the cassette from the rethermalization unit, loading the trays on the cassette and loading the cassette onto a first one of the portage units, interconnecting the portage unit loaded with the cassette to a second of the portage units, transferring the cassette loaded with the trays from the first one of the portage unit to the second one of the portage units while the portage units are interconnected, and connecting the second one of the portage units to the rethermalization unit and transferring the cassette loaded with the trays from the second one of the portage units to the rethermalization unit